GPRS support for Ofono

[Bastian, Waldo]

> > > This really belong in the kernel.  Only the kernel can reliably know
> > > when a network interface has been brought down and notify the 
> > > interested applications with the statistics.
> >
> > You're missing the point.
> >
> > Yes, any body can extract the statistics for a running context. But data
> > counters are cumulating. To compute the sum properly, there are but two
> > options:
> > # Either the GPRS middleware requests kernel per-interface statistics
> > right before destroying the interface, and sums with the earlier total.
> > # Or the modem does it internally.
> 
> I know why you want this, but I'm still against the counter being an oFono
> driver API.  There needs to be a proper kernel interface that signals the
> application when an interface has gone away with the rx/tx details.  This
> way we handle this generically for all modems without relying on some
> intrinsic hardware capabilities.

This still doesn't solve the case where the modem is accessed from a PC client and forwards PPP data as that data will not go through any network interface, e.g. BT DUN or USB tethering.

The modem is really in the best position to provide the most reliable information on data usage. You can still use statistics from the network interfaces as a fall-back in case the modem can not provide this information.

Cheers,
Waldo